Aircraft operators and owners are increasingly taking advantage of existing and emerging wireless and internet based connections to remotely upload data to aircraft. Such data is loaded into an avionics system of an aircraft at various times throughout the lifetime of the aircraft and often must be secure. Uploading files remotely exposes the aircraft to the possibility of downloading the malicious data an attacker uploaded in place of the correct data. High assurance software can detect some malicious data; however, this software is typically costly.
Typically, a database file is uploaded along with its checksum to the aircraft. The onboard system computes a second checksum of the database and compares it to the uploaded checksum. A disparity between the two checksums may indicate noise or that an error has occurred. However, this system and method is open to potential attack. For example, an attacker can attempt to change the database file and provide a corresponding checksum or change the database in a way that does not alter the original checksum. In such cases, when the onboard system receives the changed database file and its corresponding checksum, the onboard system has no way of detecting that the database file is altered. Therefore, current methods of uploading files onto an aircraft are unable to detect some forms of tampering or corruption.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for systems and methods that provide secure uploading of data onboard an aircraft.